• Preview Day is for browsing only; sales are allowed only during a four-hour period on Sales Day.

• Discounts are offered. (As a retired Air Force colonel, Mr. Hamilton this year received a military discount of 10 percent.)

• Bargaining is permitted.

“I’m very businesslike as we barter over prices,” said Mrs. Hamilton, 76. “Usually there’s some type of discount — all with proper ID, of course.”

Last year, after some dickering, he bought her a cashmere sweater for “maybe $30.”

This year, he bought several big gifts: “almost-diamond” earrings ($50, bargained down from $75); aromatherapy toiletries ($30, down from $50); and a bottle of sparkling wine with two flutes ($20, down from $25).

“He tries to bargain me down, and I try to stay tough,” said Mrs. Hamilton, noting that profits become “my mad money.”

She conceived the idea in 1995, the year she retired from the Columbus Public Utilities Department — and the year her husband forgot the holiday until the night before.

He was about to rush out to get a gift and card when his wife stopped him.

“I said: ‘Why should the store make money? I’m now retired, and why shouldn’t I make some money? Why go out and shop for me when you can shop right here at home?’ ”

“She put out stuff she’d already bought to make it easy for me,” said Mr. Hamilton, 87. “I accuse her of running a racket: She’s got it, she sells it, and she’s still got it.”

Their custom has changed his attitude about Feb. 14.

“As a young man, Valentine’s Day didn’t seem much — maybe just buy a wife or girlfriend a box of candy or flowers,” he said. “But the way we handle it now, it’s become a special renewal day, a reaffirmation of what we mean to each other.”

For 15 years running, Mr. Hamilton has bought the same card and just added fresh sentiments, which she treasures.

Granddaughter Frances Hamilton — part of a clan that includes three Hamilton children (including one who has passed away) and eight grandchildren — is one of the few who has known for years about the tradition.

“My first impression was that it was so cute,” said the 38-year-old, a resident of Delaware, Ohio.

“All this began because Grandpa was such a procrastinator. Instead of doing what a typical woman would do — get aggravated when her husband forgets the day — she turned it into something fun and beneficial for both.

“As they’ve gotten older, I think they’ve actually gotten more creative with it. Last year, he had to fill out a credit application.”She views her grandparents as role models for romance.

“Grandma and Grandpa,” she said, “have been a huge example in my life of how well a relationship can work between two people who really love each other.”